perf: lazy-load services and proxy catalogues, faster namespace strip

load_xml strips namespaces without QName; services import on first use and proxy providers fetch their catalogue on first query; the font scan is skipped when no subtitle names a font and is cached per process.

Serve CPU -40% and track requests -28% on 20 MB manifests; CLI startup 2.7 s -> 1.2 s; --list 27-46% faster across six services tested.

docs/guide/proxies-and-vpn.md

@@ -1069,8 +1069,10 @@ The returned proxy is HTTPS on **port 443**.
     methods:
 
     - `__init__(self, **kwargs)` receives its `proxy_providers` sub-dict splatted as
-      keyword arguments, so YAML keys map 1:1 to constructor parameters. Do authentication
-      and catalogue pre-fetching here.
+      keyword arguments, so YAML keys map 1:1 to constructor parameters. Check the
+      configuration here, but make no request: every `dl` run builds every configured
+      proxy provider, even for a run with no proxy. Read the server or location catalogue
+      through a `functools.cached_property`, so the first query fetches it.
     - `__repr__(self)` is a human summary, conventionally `"{n} Countries ({m} Servers)"`.
     - `get_proxy(self, query)` returns a Requests-compatible proxy URI, or `None` only
       when the query was valid but no proxy exists. Raise on genuine errors or bad queries.

tests/core/test_proxy_dispatch.py

@@ -3,6 +3,7 @@ split, the named or bare provider lookup, and the line that reports which proxy
 
 from __future__ import annotations
 
+import json
 import logging
 from typing import Iterator, Optional
 
@@ -188,10 +189,29 @@ def test_bare_query_skips_a_provider_that_raises(caplog: pytest.LogCaptureFixtur
         pick_proxy([Broken()], "us")
 
 
-def test_named_query_passes_the_provider_error_on() -> None:
+def test_named_query_passes_the_provider_error_on_as_a_value_error() -> None:
     class Broken:
         def get_proxy(self, query: str) -> str:
             raise ConnectionError("api down")
 
-    with pytest.raises(ConnectionError, match="api down"):
+    with pytest.raises(ValueError, match="The proxy provider broken failed for us: api down") as raised:
         pick_proxy([Broken()], "us", "broken")
+    assert isinstance(raised.value.__cause__, ConnectionError)
+
+
+def test_named_query_names_the_provider_for_a_bad_catalogue_response() -> None:
+    class Broken:
+        def get_proxy(self, query: str) -> str:
+            raise json.JSONDecodeError("Expecting value", "", 0)
+
+    with pytest.raises(ValueError, match="The proxy provider broken failed for us: Expecting value"):
+        pick_proxy([Broken()], "us", "broken")
+
+
+def test_named_query_passes_a_query_error_on_unchanged() -> None:
+    class Strict:
+        def get_proxy(self, query: str) -> str:
+            raise ValueError("no server for us150")
+
+    with pytest.raises(ValueError, match="^no server for us150$"):
+        pick_proxy([Strict()], "us150", "strict")

tests/core/test_proxy_loading.py

@@ -4,6 +4,7 @@ by a bare query and reported by a query that names it."""
 from __future__ import annotations
 
 import logging
+from typing import Any
 
 import pytest
 import requests
@@ -15,17 +16,14 @@ from unshackle.core.proxies.resolve import Unavailable, find_provider, load_prox
 pytestmark = pytest.mark.unit
 
 CREDENTIALS = {"username": "a" * 24, "password": "b" * 24}
+LOGIN_CREDENTIALS = {"username": "someone@example.com", "password": "hunter2"}
 OTHERS = ("basic", "expressvpn", "protonvpn", "windscribevpn", "gluetun", "hola", "controld")
 
 
 @pytest.fixture(autouse=True)
-def nordvpn_down_surfshark_up(monkeypatch: pytest.MonkeyPatch) -> None:
-    def refuse() -> list[dict]:
-        raise requests.ConnectionError("no route to api.nordvpn.com")
-
+def nordvpn_misconfigured_surfshark_up(monkeypatch: pytest.MonkeyPatch) -> None:
     clusters = [{"countryCode": "US", "connectionName": "us-dal.prod.surfshark.com", "location": "Dallas"}]
-    monkeypatch.setattr(config, "proxy_providers", {"nordvpn": CREDENTIALS, "surfsharkvpn": CREDENTIALS})
-    monkeypatch.setattr(NordVPN, "get_countries", staticmethod(refuse))
+    monkeypatch.setattr(config, "proxy_providers", {"nordvpn": LOGIN_CREDENTIALS, "surfsharkvpn": CREDENTIALS})
     monkeypatch.setattr(SurfsharkVPN, "get_countries", staticmethod(lambda: clusters))
 
 
@@ -49,7 +47,7 @@ def test_query_naming_another_provider_still_works() -> None:
 
 @pytest.mark.parametrize("name", ["nordvpn", "NordVPN"])
 def test_query_naming_the_failed_provider_reports_why(name: str) -> None:
-    with pytest.raises(ValueError, match="NordVPN could not load: no route to api.nordvpn.com"):
+    with pytest.raises(ValueError, match="NordVPN could not load: NordVPN needs its Service Credentials"):
         resolve_proxy(f"{name}:us", load_proxy_providers(OTHERS))
 
 
@@ -59,10 +57,29 @@ def test_query_naming_an_unknown_provider_lists_the_loaded_ones() -> None:
 
 
 def test_raise_errors_raises_the_load_failure() -> None:
-    with pytest.raises(requests.ConnectionError):
+    with pytest.raises(ValueError, match="Service Credentials"):
         load_proxy_providers(OTHERS, raise_errors=True)
 
 
+def test_catalogue_is_fetched_on_first_use_and_a_failed_fetch_fails_only_its_query(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    calls = []
+
+    def refuse() -> list[dict]:
+        calls.append(1)
+        raise requests.ConnectionError("no route to api.nordvpn.com")
+
+    monkeypatch.setattr(config, "proxy_providers", {"nordvpn": CREDENTIALS, "surfsharkvpn": CREDENTIALS})
+    monkeypatch.setattr(NordVPN, "get_countries", staticmethod(refuse))
+    nordvpn, surfshark = load_proxy_providers(OTHERS)
+    assert isinstance(nordvpn, NordVPN) and not calls
+
+    assert resolve_proxy("us", [nordvpn, surfshark]).endswith("@us-dal.prod.surfshark.com:443")
+    with pytest.raises(ValueError, match="nordvpn failed for us: no route to api.nordvpn.com"):
+        resolve_proxy("nordvpn:us", [nordvpn, surfshark])
+
+
 def test_bare_query_order_follows_config_key_order_with_controld_last(monkeypatch: pytest.MonkeyPatch) -> None:
     from unshackle.core.proxies import ControlD
 
@@ -88,3 +105,71 @@ def test_rest_path_loads_windscribe_but_not_gluetun(monkeypatch: pytest.MonkeyPa
     assert any(isinstance(p, WindscribeVPN) for p in providers)
     assert not any(isinstance(p, Gluetun) or getattr(p, "name", None) == "Gluetun" for p in providers)
     assert resolve_proxy("windscribevpn:us", providers).endswith("@us-central-1.example:443")
+
+
+def build_controld() -> Any:
+    from unshackle.core.proxies import ControlD
+
+    return ControlD(token="t")
+
+
+def build_hola(monkeypatch: pytest.MonkeyPatch) -> Any:
+    from unshackle.core import binaries
+    from unshackle.core.proxies import Hola
+
+    monkeypatch.setattr(binaries, "HolaProxy", "hola-proxy")
+    return Hola()
+
+
+@pytest.mark.parametrize(
+    ("name", "fetch", "attr"),
+    [
+        ("NordVPN", "get_countries", "countries"),
+        ("WindscribeVPN", "get_countries", "countries"),
+        ("SurfsharkVPN", "get_countries", "countries"),
+        ("ControlD", "get_locations", "catalogue"),
+        ("Hola", "get_countries", "countries"),
+    ],
+)
+def test_construction_makes_no_request_and_the_first_read_fetches_once(
+    name: str, fetch: str, attr: str, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    from unshackle.core import proxies
+
+    cls = getattr(proxies, name)
+    calls: list[int] = []
+
+    def counted(*args: Any) -> list[dict]:
+        calls.append(1)
+        return [{"country": "US"}]
+
+    is_static = isinstance(vars(cls)[fetch], staticmethod)
+    monkeypatch.setattr(cls, fetch, staticmethod(counted) if is_static else counted)
+    if name == "ControlD":
+        provider = build_controld()
+    elif name == "Hola":
+        provider = build_hola(monkeypatch)
+    else:
+        provider = cls(**CREDENTIALS)
+    assert not calls
+
+    assert getattr(provider, attr) == [{"country": "US"}]
+    getattr(provider, attr)
+    assert calls == [1]
+
+
+def test_health_probe_reads_each_proxy_catalogue(monkeypatch: pytest.MonkeyPatch) -> None:
+    from unshackle.core.api.handlers import run_health_checks
+
+    calls: list[int] = []
+
+    def countries() -> list[dict]:
+        calls.append(1)
+        return [{"serverCount": 3}]
+
+    monkeypatch.setattr(config, "key_vaults", [])
+    monkeypatch.setattr(config, "proxy_providers", {"nordvpn": CREDENTIALS})
+    monkeypatch.setattr(NordVPN, "get_countries", staticmethod(countries))
+    detail = {c["id"]: c for c in run_health_checks()}["proxies"]["detail"]
+    assert calls == [1]
+    assert "NordVPN (1 Country (3 Servers))" in detail

tests/core/test_services_lazy.py

@@ -0,0 +1,143 @@
+"""Services import on first use: a command pays only for the service it runs."""
+
+from __future__ import annotations
+
+import logging
+import sys
+import threading
+from pathlib import Path
+
+import click
+import pytest
+from aiohttp import web
+
+from unshackle.core import binaries, services
+from unshackle.core.config import config
+
+pytestmark = pytest.mark.unit
+
+EXAMPLE_SOURCE = """\
+import click
+
+
+class EXAMPLE:
+    ALIASES = ("ex",)
+
+    @staticmethod
+    def get_binaries():
+        return [{"name": "ExampleTool", "desc": "example dependency"}]
+
+    @staticmethod
+    @click.command()
+    def cli():
+        pass
+"""
+
+
+@pytest.fixture
+def two_services(tmp_path: Path, monkeypatch: pytest.MonkeyPatch):
+    for tag, body in (("EXAMPLE", EXAMPLE_SOURCE), ("OTHER", "raise ImportError('boom')\n")):
+        (tmp_path / tag).mkdir()
+        (tmp_path / tag / "__init__.py").write_text(body)
+    monkeypatch.setattr(services, "SERVICES", [tmp_path / t / "__init__.py" for t in ("EXAMPLE", "OTHER")])
+    monkeypatch.setattr(services, "MODULES", {})
+    monkeypatch.setattr(services, "ALIASES", {})
+    monkeypatch.setattr(services, "LOAD_ERRORS", [])
+    monkeypatch.setattr(services, "SHADOWED", [])
+    monkeypatch.setattr(services, "DIRTY_REPOS", [])
+    monkeypatch.setattr(services, "SUMMARY_LOGGED", False)
+    monkeypatch.setattr(binaries, "_registered_binaries", {})
+    monkeypatch.setattr(binaries, "__binaries", dict(getattr(binaries, "__binaries")))
+    yield
+    for name in ("EXAMPLE", "OTHER"):
+        sys.modules.pop(name, None)
+
+
+def test_a_tag_imports_only_its_own_service(two_services: None) -> None:
+    assert services.Services.get_tag("example") == "EXAMPLE"
+    assert services.MODULES == {}
+
+    assert services.Services.load("EXAMPLE").__name__ == "EXAMPLE"
+    assert list(services.MODULES) == ["EXAMPLE"] and not services.LOAD_ERRORS
+    assert [d["name"] for d in binaries.get_registered_dependencies()] == ["ExampleTool"]
+
+
+def test_an_alias_imports_services_until_one_matches(two_services: None) -> None:
+    assert services.Services.get_tag("ex") == "EXAMPLE"
+    assert list(services.MODULES) == ["EXAMPLE"]
+
+
+def test_a_failed_import_fails_only_its_own_tag_and_is_not_retried(two_services: None) -> None:
+    with pytest.raises(KeyError):
+        services.Services.load("OTHER")
+    assert len(services.LOAD_ERRORS) == 1 and services.LOAD_ERRORS[0].startswith("OTHER: ")
+    services.ensure_loaded("OTHER")
+    assert len(services.LOAD_ERRORS) == 1
+
+    services.check_load_errors("EXAMPLE")
+    with pytest.raises(click.ClickException, match="Failed to load 1 service"):
+        services.check_load_errors("OTHER")
+
+
+def test_get_command_runs_a_good_service_beside_a_broken_one(two_services: None) -> None:
+    group = services.Services(name="dl")
+    ctx = click.Context(group)
+    with pytest.raises(click.ClickException, match="OTHER: failed to import"):
+        group.get_command(ctx, "OTHER")
+    assert group.get_command(ctx, "EXAMPLE").name == "EXAMPLE"
+
+
+def test_get_tag_does_not_wait_for_a_reload_on_a_failed_tag(two_services: None) -> None:
+    services.ensure_loaded("EXAMPLE")
+    services.ensure_loaded("OTHER")
+    held, release = threading.Event(), threading.Event()
+
+    def reload() -> None:
+        with services.RELOAD_LOCK:
+            held.set()
+            release.wait()
+
+    holder = threading.Thread(target=reload)
+    holder.start()
+    try:
+        assert held.wait(5)
+        result: list[str] = []
+        lookup = threading.Thread(target=lambda: result.append(services.Services.get_tag("nosuch")))
+        lookup.start()
+        lookup.join(5)
+        assert result == ["nosuch"]
+    finally:
+        release.set()
+        holder.join()
+
+
+def test_load_all_imports_every_service(two_services: None) -> None:
+    services.load_all()
+    assert list(services.MODULES) == ["EXAMPLE"]
+    assert services.ALIASES == {"EXAMPLE": ("ex",)}
+    assert services.failed_tags(services.LOAD_ERRORS) == {"OTHER"}
+
+
+def test_env_dependencies_list_every_service_binary(two_services: None) -> None:
+    from unshackle.commands.env import get_dependencies
+
+    assert "ExampleTool" in {dep["name"] for dep in get_dependencies()}
+
+
+def test_serve_startup_imports_every_service(two_services: None, monkeypatch: pytest.MonkeyPatch) -> None:
+    from unshackle.commands.serve import _install_service_refresh
+
+    monkeypatch.setattr(config, "serve", {})
+    _install_service_refresh(web.Application())
+    assert list(services.MODULES) == ["EXAMPLE"]
+
+
+def test_a_run_of_one_tag_names_its_duplicate(two_services: None, caplog: pytest.LogCaptureFixture) -> None:
+    services.SHADOWED[:] = [
+        "EXAMPLE: using /a/EXAMPLE, ignoring /b/EXAMPLE",
+        "OTHER: using /a/OTHER, ignoring /b/OTHER",
+    ]
+    with caplog.at_level(logging.INFO, logger="services"):
+        services.check_load_errors("EXAMPLE")
+    assert "EXAMPLE: 1 duplicate(s) ignored" in caplog.text
+    assert "OTHER" not in caplog.text

unshackle/commands/dl.py

@@ -607,6 +607,8 @@ class dl:
         Returns:
             Tuple of (fonts_attached_count, missing_fonts_list)
         """
+        if not font_names:
+            return 0, []
         system_fonts = get_system_fonts()
 
         font_count = 0

unshackle/commands/env.py

@@ -13,7 +13,7 @@ from unshackle.core import binaries
 from unshackle.core.config import POSSIBLE_CONFIG_PATHS, config, config_path
 from unshackle.core.console import console, listing_table, print_wide
 from unshackle.core.constants import context_settings
-from unshackle.core.services import Services
+from unshackle.core.services import Services, load_all
 from unshackle.core.temp import TASK_PREFIX, is_stale
 
 
@@ -134,6 +134,7 @@ def get_dependencies() -> list[dict]:
         },
     ]
 
+    load_all()
     for reg in binaries.get_registered_dependencies():
         deps.append(
             {

unshackle/commands/serve.py

@@ -76,6 +76,7 @@ def _install_service_refresh(app: web.Application) -> None:
     from unshackle.core import services
 
     log = logging.getLogger("serve")
+    services.load_all()
     services.log_load_issues()
     services.record_loaded_commits()
     interval = int(config.serve.get("services_refresh_interval", 0) or 0)
@@ -575,7 +576,11 @@ def serve(
             app["config"] = serve_config
             app["debug_api"] = debug_api
 
-            if not cdm_only:
+            if cdm_only:
+                from unshackle.core import services
+
+                services.load_all()
+            else:
                 _install_session_store(app)
                 _install_service_refresh(app)
             _install_config_reload(app, no_key=no_key, serve_widevine=serve_widevine, serve_playready=serve_playready)

unshackle/core/api/handlers.py

@@ -3020,10 +3020,11 @@ def run_health_checks(checks: Optional[List[Dict[str, Any]]] = None) -> List[Dic
     checks.append(health_check("bad_keys", "bad content key flags", bad_keys_probe))
 
     def proxy_probe() -> tuple[str, str]:
+        """Render each proxy provider, because the render fetches its catalogue from the provider."""
         providers = initialize_proxy_providers(raise_errors=True, quiet=True)
         if not providers:
             return "ok", "none configured"
-        return "ok", ", ".join(type(p).__name__ for p in providers)
+        return "ok", ", ".join(f"{type(p).__name__} ({p!r})" for p in providers)
 
     if config.proxy_providers:
         checks.append(health_check("proxies", "proxy providers", proxy_probe, config_secrets(config.proxy_providers)))

unshackle/core/proxies/controld.py

@@ -9,6 +9,7 @@ import socket
 import socketserver
 import threading
 import time
+from functools import cached_property
 from typing import Optional
 from urllib.parse import urlsplit
 
@@ -361,7 +362,10 @@ class ControlD(Proxy):
         self.resolvers = dict(self.configured)
         self.last_profile: Optional[str] = None
 
-        self.catalogue = self.get_locations()
+    @cached_property
+    def catalogue(self) -> list[dict]:
+        """Fetched on first use, so a run that wants no proxy makes no request."""
+        return self.get_locations()
 
     def __repr__(self) -> str:
         countries = len({x["country"] for x in self.catalogue})
@@ -377,7 +381,7 @@ class ControlD(Proxy):
             response.raise_for_status()
             return response.json()["body"]["proxies"]
         except Exception as e:
-            # never fail the command: all providers load up front, even for a run that wants no proxy
+            # never fail the command: a bare query falls through to the next proxy provider
             log.warning(f"Could not read Control D's locations: {e}")
             return []
 

unshackle/core/proxies/hola.py

@@ -1,6 +1,7 @@
 import random
 import re
 import subprocess
+from functools import cached_property
 from typing import Optional
 
 from unshackle.core import binaries
@@ -16,7 +17,10 @@ class Hola(Proxy):
             raise EnvironmentError("hola-proxy executable not found but is required for the Hola proxy provider.")
         self.binary = binaries.HolaProxy
 
-        self.countries = self.get_countries()
+    @cached_property
+    def countries(self) -> list[dict[str, str]]:
+        """Fetched on first use, so a run that wants no proxy makes no request."""
+        return self.get_countries()
 
     def __repr__(self) -> str:
         countries = len(self.countries)

unshackle/core/proxies/nordvpn.py

@@ -1,6 +1,7 @@
 import json
 import random
 import re
+from functools import cached_property
 from typing import Optional, Union
 
 import requests
@@ -33,7 +34,10 @@ class NordVPN(Proxy):
         self.server_map = server_map or {}
         self.last_hostname: Optional[str] = None
 
-        self.countries = self.get_countries()
+    @cached_property
+    def countries(self) -> list[dict]:
+        """Fetched on first use, so a run that wants no proxy makes no request."""
+        return self.get_countries()
 
     def __repr__(self) -> str:
         countries = len(self.countries)

unshackle/core/proxies/proxy.py

@@ -12,7 +12,7 @@ F = TypeVar("F", bound=Callable[..., Any])
 def cached_catalogue(fetch: F) -> F:
     """Keep a proxy provider's catalogue for ``CATALOGUE_TTL`` seconds; a failed (empty) answer is fetched again.
 
-    A server builds its proxy providers on every request, and each build fetches the catalogue.
+    A server builds its proxy providers on every request, and the first query on each one reads the catalogue.
     One config builds every provider, so a config reload clears the cache.
     """
 
@@ -33,9 +33,10 @@ class Proxy:
     @abstractmethod
     def __init__(self, **kwargs: Any) -> None:
         """
-        The constructor initializes the Service using passed configuration data.
+        The constructor initialises the proxy provider from its configuration data.
 
-        Any authorization or pre-fetching of data should be done here.
+        Check the configuration here, but make no request: every run builds every configured proxy provider,
+        even a run with no proxy. Fetch a catalogue on first use, through a ``functools.cached_property``.
         """
 
     @abstractmethod

unshackle/core/proxies/resolve.py

@@ -3,12 +3,14 @@
 from __future__ import annotations
 
 import ipaddress
+import json
 import logging
 import re
 from typing import Any, List, Optional
 from urllib.parse import urlparse
 
 import click
+import requests
 from click.core import ParameterSource
 
 from unshackle.core.proxies.proxy import Proxy
@@ -58,6 +60,7 @@ def load_proxy_providers(exclude: tuple[str, ...] = (), raise_errors: bool = Fal
 
     Each proxy provider loads on its own. One that fails is logged and kept as Unavailable, so a bare
     query skips it and a query that names it reports why. *raise_errors* raises the failure instead.
+    The first query fetches a catalogue, not this function.
     *exclude* holds lowercase class names to leave out.
     """
     from unshackle.core import binaries
@@ -106,7 +109,7 @@ def load_proxy_providers(exclude: tuple[str, ...] = (), raise_errors: bool = Fal
             if provider is None:
                 continue
             if not quiet:
-                log.info(f"Loaded {name}: {provider}")
+                log.info(f"Loaded {name}")
         except Exception as e:
             if raise_errors:
                 raise
@@ -122,8 +125,7 @@ def initialize_proxy_providers(raise_errors: bool = False, quiet: bool = False)
     Load the proxy providers for the REST API and the remote service client.
 
     Gluetun is not offered on this path, because it starts a local Docker container. *quiet* drops the
-    per-provider summary lines: rendering a proxy provider asks some of them for their server catalogue
-    over the network, which a repeated caller must not pay for.
+    per-provider summary lines.
     """
     proxy_providers = load_proxy_providers(("gluetun",), raise_errors, quiet)
     if not quiet and not proxy_providers:
@@ -154,12 +156,17 @@ def pick_proxy(proxy_providers: List[Any], query: str, provider_name: Optional[s
     """
     Get a proxy provider and its proxy URI: from the named one, or else from the first one that answers.
 
-    A named proxy provider's error goes to the caller. In a bare query, a proxy provider that fails is
+    A named proxy provider's error goes to the caller as a ValueError. In a bare query, a proxy provider that fails is
     logged and skipped, so a later one can still answer. Raises ValueError when no proxy provider answers.
     """
     if provider_name:
         provider = find_provider(proxy_providers, provider_name)
-        uri = provider.get_proxy(query)
+        try:
+            uri = provider.get_proxy(query)
+        except Exception as e:
+            if isinstance(e, ValueError) and not isinstance(e, (json.JSONDecodeError, requests.RequestException)):
+                raise
+            raise ValueError(f"The proxy provider {provider_name} failed for {query}: {e}") from e
         if not uri:
             raise ValueError(f"The proxy provider {provider_name} had no proxy for {query}")
         return provider, uri

unshackle/core/proxies/surfsharkvpn.py

@@ -6,7 +6,7 @@ import re
 import socket
 import ssl
 import threading
-from functools import cache, partial
+from functools import cache, cached_property, partial
 from typing import Optional
 
 import certifi
@@ -119,7 +119,11 @@ class SurfsharkVPN(Proxy):
             self.server_map[COUNTRY_CODE_ALIASES.get(country, country) + sep + city] = server
 
         self.last_server: Optional[tuple[str, str]] = None
-        self.countries = self.get_countries()
+
+    @cached_property
+    def countries(self) -> list[dict]:
+        """Fetched on first use, so a run that wants no proxy makes no request."""
+        return self.get_countries()
 
     def __repr__(self) -> str:
         countries = len(set(x.get("country") for x in self.countries if x.get("country")))

unshackle/core/proxies/windscribevpn.py

@@ -1,6 +1,7 @@
 import json
 import random
 import re
+from functools import cached_property
 from typing import Iterator, Optional
 
 import requests
@@ -33,7 +34,10 @@ class WindscribeVPN(Proxy):
         self.server_map = server_map or {}
         self.last_hostname: Optional[str] = None
 
-        self.countries = self.get_countries()
+    @cached_property
+    def countries(self) -> list[dict]:
+        """Fetched on first use, so a run that wants no proxy makes no request."""
+        return self.get_countries()
 
     def __repr__(self) -> str:
         countries = len(set(x.get("country_code") for x in self.countries if x.get("country_code")))

unshackle/core/services.py

@@ -108,24 +108,6 @@ def load_service(path: Path) -> type[Service]:
         ) from e
 
 
-def load_services(paths: list[Path]) -> tuple[dict[str, type[Service]], list[str]]:
-    """Load every Service, returning the good ones plus a list of load errors.
-
-    Importing this module must never raise: several commands import it, and Python
-    does not cache a failed import, so raising here would re-run and re-report for
-    every command. Instead we collect failures and let the caller surface them once,
-    cleanly, when it uses the services.
-    """
-    modules: dict[str, type[Service]] = {}
-    errors: list[str] = []
-    for path in paths:
-        try:
-            modules[path.parent.stem] = load_service(path)
-        except Exception as e:
-            errors.append(str(e))
-    return modules, errors
-
-
 def register_service_binaries(modules: dict[str, type[Service]]) -> None:
     """Register custom binary dependencies declared by services via get_binaries()."""
 
@@ -144,15 +126,46 @@ def register_service_binaries(modules: dict[str, type[Service]]) -> None:
                 log.warning(f"Failed to register custom binaries for service {tag}: {e}")
 
 
-MODULES, LOAD_ERRORS = load_services(SERVICES)
-register_service_binaries(MODULES)
-
-ALIASES = {tag: getattr(module, "ALIASES", ()) for tag, module in MODULES.items()}
+MODULES: dict[str, type[Service]] = {}
+LOAD_ERRORS: list[str] = []
+ALIASES: dict[str, tuple[str, ...]] = {}
 
 PENDING: set[str] = set()
 PENDING_SINCE: dict[str, float] = {}
 LOADED_COMMITS: dict[str, str] = {}
-RELOAD_LOCK = threading.Lock()
+RELOAD_LOCK = threading.RLock()
+
+
+def ensure_loaded(tag: str) -> type[Service] | None:
+    """Import one discovered service on first use; None when the tag is unknown or its import failed.
+
+    Startup imports no service: a command that runs one service pays only for that one.
+    A failed import is kept in ``LOAD_ERRORS`` and is not tried again until a reload.
+    """
+    service = MODULES.get(tag)
+    if service is not None or tag in failed_tags(LOAD_ERRORS):
+        return service
+    with RELOAD_LOCK:
+        if tag in MODULES or tag in failed_tags(LOAD_ERRORS):
+            return MODULES.get(tag)
+        path = next((path for path in SERVICES if path.parent.stem == tag), None)
+        if path is None:
+            return None
+        try:
+            service = load_service(path)
+        except Exception as e:
+            LOAD_ERRORS.append(str(e))
+            return None
+        MODULES[tag] = service
+        ALIASES[tag] = getattr(service, "ALIASES", ())
+        register_service_binaries({tag: service})
+        return service
+
+
+def load_all() -> None:
+    """Import every discovered service, for the callers that need all of them (help, serve, env)."""
+    for tag in Services.get_tags():
+        ensure_loaded(tag)
 
 
 def record_loaded_commits(tags: Iterable[str] | None = None) -> None:
@@ -320,7 +333,7 @@ def log_load_issues() -> None:
         log.error(f"Service skipped: {err}")
 
 
-def check_load_errors() -> None:
+def check_load_errors(tag: str | None = None) -> None:
     """Log a one-line load summary (once) and raise a single clean error on failures.
 
     unshackle calls this when it needs the services (listing/resolving), so Click
@@ -328,23 +341,27 @@ def check_load_errors() -> None:
     command that imports this module. This function summarises the duplicate services
     (a tag that an earlier, higher-priority source also gives, and which unshackle
     ignores). The full list - naming the path used and the duplicate ignored - is
-    debug-only.
+    debug-only. With *tag*, only that service's load error counts, and the summary names
+    only a duplicate of that tag.
     """
     if DIRTY_REPOS:
         joined = "\n".join(f"  - {p}" for p in DIRTY_REPOS)
         raise click.ClickException("Service repo has local changes, not refreshing:\n" + joined)
+    errors = [err for err in LOAD_ERRORS if tag is None or err.startswith(f"{tag}: ")]
+    if errors:
+        joined = "\n".join(f"  - {err}" for err in errors)
+        raise click.ClickException(f"Failed to load {len(errors)} service(s):\n{joined}")
     global SUMMARY_LOGGED
-    if not SUMMARY_LOGGED:
-        SUMMARY_LOGGED = True
-        summary = f"Loaded {len(MODULES)} services"
-        if SHADOWED:
-            summary += f" ({len(SHADOWED)} duplicate(s) ignored)"
-        log.info(summary)
-        for shadow in SHADOWED:
-            log.debug("%s", shadow)
-    if LOAD_ERRORS:
-        joined = "\n".join(f"  - {err}" for err in LOAD_ERRORS)
-        raise click.ClickException(f"Failed to load {len(LOAD_ERRORS)} service(s):\n{joined}")
+    if SUMMARY_LOGGED:
+        return
+    SUMMARY_LOGGED = True
+    shadows = SHADOWED if tag is None else [shadow for shadow in SHADOWED if shadow.startswith(f"{tag}: ")]
+    if tag is None:
+        log.info(f"Loaded {len(MODULES)} services" + (f" ({len(SHADOWED)} duplicate(s) ignored)" if SHADOWED else ""))
+    elif shadows:
+        log.info(f"{tag}: {len(shadows)} duplicate(s) ignored")
+    for shadow in shadows:
+        log.debug("%s", shadow)
 
 
 ROUTING_PARAMS = ("remote", "server")
@@ -395,12 +412,12 @@ class Services(click.Group):
                     if remote_tag not in tags:
                         tags.append(remote_tag)
             return tags
+        load_all()
         check_load_errors()
         return Services.get_tags()
 
     def get_command(self, ctx: click.Context, name: str) -> click.Command:
         """Load the Service and return the Click CLI method."""
-        check_load_errors()
         tag = Services.get_tag(name)
 
         if Services.is_import(ctx):
@@ -411,6 +428,8 @@ class Services(click.Group):
         if remote:
             return Services.make_remote_command(name, routing.get("server"))
 
+        ensure_loaded(tag)
+        check_load_errors(tag)
         try:
             service = Services.load(tag)
         except KeyError as e:
@@ -608,6 +627,8 @@ class Services(click.Group):
                 return tag
 
         for tag in tags:
+            if tag not in ALIASES:
+                ensure_loaded(tag)
             if any(value_lower == alias.lower() for alias in ALIASES.get(tag, ())):
                 return tag
 
@@ -616,7 +637,7 @@ class Services(click.Group):
     @staticmethod
     def load(tag: str) -> type[Service]:
         """Load a Service module by Service tag."""
-        module = MODULES.get(tag)
+        module = ensure_loaded(tag)
         if module:
             return module
 

unshackle/core/utilities.py

@@ -897,9 +897,10 @@ def get_unix_fonts() -> dict[str, Path]:
     return fonts
 
 
+@cache
 def get_system_fonts() -> dict[str, Path]:
     """
-    Get system fonts as a mapping of font family names to font file paths.
+    Get system fonts as a mapping of font family names to font file paths, scanned once per process.
 
     On Windows: Uses registry to get font display names
     On Linux/macOS: Scans standard font directories and extracts family names using fontTools

unshackle/core/utils/xml.py

@@ -5,20 +5,19 @@ from lxml.etree import ElementTree
 
 
 def load_xml(xml: Union[str, bytes]) -> ElementTree:
-    """Safely parse XML data to an ElementTree, without namespaces in tags."""
+    """Safely parse XML data to an ElementTree, without namespaces in tags.
+
+    The strip uses string operations, not etree.QName: on a 20 MB manifest the QName walk costs several times the parse.
+    """
     if not isinstance(xml, bytes):
         xml = xml.encode("utf8")
     root = etree.fromstring(xml)
-    for elem in root.getiterator():
-        if not hasattr(elem.tag, "find"):
-            # e.g. comment elements
-            continue
-        elem.tag = etree.QName(elem).localname
-        for name, value in elem.attrib.items():
-            local_name = etree.QName(name).localname
-            if local_name == name:
-                continue
-            del elem.attrib[name]
-            elem.attrib[local_name] = value
+    for elem in root.iter(etree.Element):
+        tag = elem.tag
+        if tag[0] == "{":
+            elem.tag = tag.partition("}")[2]
+        attrib = elem.attrib
+        for name in [name for name in attrib if name[0] == "{"]:
+            attrib[name.partition("}")[2]] = attrib.pop(name)
     etree.cleanup_namespaces(root)
     return root